Gravitational waves are the “soundtrack of the universe”

On Thursday, February 11th 2016, scientists at National Science Foundation and Caltech said that they have finally detected gravitational waves, the ripples in the fabric of space-time that Einstein predicted a century ago.

Scientists found indirect proof of the existence of gravitational waves in the 1970s – computations that showed they ever so slightly changed the orbits of two colliding stars – and the work was honored as part of the 1993 Nobel Prize in physics. But Thursday’s announcement was a direct detection of a gravitational wave.

And that’s considered a big difference.

“It’s one thing to know soundwaves exist, but it’s another to actually hear Beethoven’s Fifth Symphony,” said Marc Kamionkowsi, a physicist at Johns Hopkins University who wasn’t part of the discovery team. “In this case we’re actually getting to hear black holes merging.”

Gravitational waves are the “soundtrack of the universe,” said team member Chad Hanna of Pennsylvania State University.

Detecting gravitational waves is so difficult that when Einstein first theorized about them, he figured scientists would never be able to hear them. Einstein later doubted himself and even questioned in the 1930s whether they really do exist, but by the 1960s scientists had concluded they probably do, Ashtekar said.

In 1979, the National Science Foundation decided to give money to the California Institute of Technology and the Massachusetts Institute of Technology to come up with a way to detect the waves.

Twenty years later, they started building two LIGO detectors in Hanford, Washington, and Livingston, Louisiana, and they were turned on in 2001. But after years with no luck, scientists realized they had to build a more advanced detection system, which was turned on last September.

“This is truly a scientific moonshot and we did it. We landed on the moon,” said David Reitze, LIGO’s executive director.